Photo-alignable object

ABSTRACT

The present invention relates to a method for manufacturing a photo-alignable object. The invention further provides compositions for the manufacturing of a photo-alignable object as well as different embodiments of photo-alignable objects and devices using them.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a National Stage of International Application No.PCT/EP2014/067196, filed Aug. 12, 2014, claiming priority based onEuropean Patent Application Nos. 13180803.2 filed Aug. 19, 2013, and13198795.0 filed Dec. 20, 2013, the contents of all of which areincorporated herein by reference in their entirety.

TECHNICAL FIELD

The invention relates to objects with photo-alignment properties andmethods for its preparation.

BACKGROUND OF THE INVENTION

Recently, photo-alignment has been successfully introduced in largescale production of liquid crystal displays (LCD) and anisotropicoptical films for various applications, such as 3D-converter films, alsoknown as film patterned retarders, for passive 3D television andmonitors. In each of above applications, thin photo-alignment layers areemployed to align liquid crystals. In case the photo-alignment layer isused inside a liquid crystal panel to align the switchable liquidcrystals, the alignment property of the photo-alignment layer has to bemaintained over the lifetime of the display since the liquid crystalmaterial has to be realigned each time it has been switched due tointeraction with an applied electrical field. In case of anisotropicoptical films the liquid crystals are cross-linked after they have beenaligned by the photo-alignment layer. Specific embodiments can, forexample, be found in U.S. Pat. No. 6,717,644.

Compared to conventional alignment of liquid crystals by brushedsurfaces, the photo-alignment technique has many advantages, such ashigh reproducibility, alignment patterning and suitability for roll toroll manufacturing. In addition, photo-alignment can be applied oncurved surfaces, such as lenses, since the light which generates thealignment in the photo-alignment layers can follow the surfacemodulation, which is not the case for most of the alternative alignmentmethods. In the state of the art photo-alignment technique thin layersof photo-alignment materials are applied to a substrate, such as a glassplate or a plastic foil. Since the alignment information is transferredby the surface of the alignment layers, its thickness is less importantand device manufacturers choose low thickness to reduce material costs.A typical thickness of photo-alignment layers in the state of the art isaround 100 nm or less. This is in particular the case for application asalignment layers in LCDs, where thicker layers have the disadvantagethat they lead to an increase of the effective threshold voltage forswitching the LCD.

As long as the substrates are flat or slightly curved there aredifferent standard coating techniques which can be used to homogeneouslyapply the photo-alignment layer. However, if a photo-alignment layer hasto be applied to a substrate comprising smaller structures, for examplemicrostructures, such as micro lenses or micro-prisms, or structuresexhibiting abrupt changes of the shape, such as rectangular structures,coating of a thin homogeneous layer is more complex and depending on thespecific application, may even be impossible.

A further drawback of the state of the art photo-alignment technique isthat the substrates which are used as a support for materials which needto be aligned, such as liquid crystals, have first to be coated with athin photo-alignment layer, which increases costs and manufacturing timeand reduces the production yield.

SUMMARY OF THE INVENTION

The goal of the present invention is to provide a solution, whichovercomes above mentioned drawbacks of the state of the artphoto-alignment technique.

The invention includes a method for manufacturing a photo-alignableobject. The invention further provides compositions for themanufacturing of a photo-alignable object. The invention also providesdifferent embodiments of photo-alignable objects as well as devicesincorporating such objects.

In the method according to the invention an object is manufactured froma material composition, which comprises a photo-alignable material. Themethod of the invention differs from that of the state of the artphoto-alignment technique that the object itself is photo-alignable andan additional deposition of a thin photo-alignment layer is notrequired. This has the advantage that the number of coating steps isreduced, which increases yield in production.

Accordingly, a method of the invention for preparation of aphoto-alignable object comprises the steps of

-   -   providing a material composition comprising a photo-alignable        material    -   generation of an object from the material composition.

The material composition may consist of the photo-alignable materialalone or it may comprise additional substances. Preferably, the materialcomposition comprises at least one photo-alignable material and at leastone additional substance, wherein the materials are so selected that inan object prepared from the composition phase separation can occur, suchthat the concentration of at least one sort of photo-alignable materialis higher at least at one surface of the object than in the bulk of theobject.

An object in the meaning of this application can have any form or shape.For example, it may be a body with complex surfaces. In a preferredembodiment, the object is a flexible foil. In another preferredembodiment, the object comprises topographical surface structures, suchas microstructures like micro lenses or micro-prisms, or structuresexhibiting abrupt changes of the shape, such as rectangular structures.

The object may be generated by any suitable method like, extruding,casting, molding, 2D- or 3D-printing or coating.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is further illustrated by the accompanying drawingfigures. It is emphasized that the various features are not necessarilydrawn to scale.

FIG. 1 depicts an example of the state of the art photo-alignmenttechnique, where a thin photo-alignment layer is applied to a support.

FIG. 2 shows an application, in which a photo-alignable object with asurface structure has been used to align a slave material on top.

FIG. 3 shows a cell, wherein a liquid crystal is aligned by twophoto-aligned objects.

FIGS. 4a, 4b and 4c illustrate an example of generating aphoto-alignable object with surface structures.

FIGS. 5a and 5b illustrate a method of generating a photo-alignableobject with surface structures by imprinting.

FIGS. 6a, 6b, 6c and 6d show a method for generating opticallyanisotropic lenses using a photo-aligned object with surface structures.

DETAILED DESCRIPTION OF THE INVENTION

According to a first aspect of the invention there is provided a methodfor manufacturing a photo-alignable object.

In the context of the present application a photo-alignable object shallmean an object, which comprises a photo-alignable material.

The method of the invention for preparation of a photo-alignable objectcomprises the steps of

-   -   providing a material composition comprising a photo-alignable        material    -   generation of an object from the material composition

An object according to the invention may have any form. For example, anobject may have the form of a sphere, a cube, a cylinder, a tube, asleeve, a foil, a lens, an ellipsoid, a cuboid, a torus, a cone, awedge, a pyramid or a prism. An object may be flat or curved, rigid orflexible. Although the above examples of objects are only basicgeometrical forms, which were chosen to illustrate the scope of theinvention, the term object shall include any other object, which mayhave much more complex shapes and surfaces.

The object may, for example, be a free standing film. A free standingfilm may be prepared directly, for example by extrusion, or the objectmade from the material composition may be generated as a film on asupport, which in a further step it is removed from the support.

To characterize the dimension of an object according to the invention,the thickness of the object shall be defined as the maximum thicknessalong the thickness direction of the object. The thickness directionshall be the direction of the smallest dimension of the object. Forexample, in case of a foil, the thickness direction is perpendicular tothe foil surface. In case the object has a topographical surfacestructure along the thickness direction, the thickness shall be measuredup to the top of the structure, as this is indicated in FIG. 2 by thethickness d of the object 11.

The thickness of an object according to the invention is larger than 200nm. Preferably, the thickness of the object is larger than 500 nm, morepreferable larger than 2 μm and most preferable larger than 10 μm. Forsome applications, for example, if the object is intended not to be on asupport during or after its manufacture, the thickness of the object ispreferably larger than 50 μm, more preferable larger than 200 μm andmost preferable larger than 1 mm.

In the context of the present application, a “photo-alignable material”is a material in which anisotropic properties can be induced uponexposure to aligning light. Analogously, a “photo-alignable object” isan object in which anisotropic properties can be induced upon exposureto aligning light. In addition, the terms “photo-aligned material” and“photo-aligned object” are used to refer to photo-alignable materialsand photo-alignable objects that have been aligned by exposure toaligning light.

In the context of the present application, the term “aligning light”shall mean light, which can induce anisotropy in a photo-alignablematerial and which is at least partially linearly or ellipticallypolarized and/or is incident to the surface of a photo-alignablematerial from an oblique direction. Preferably, the aligning light islinearly polarized with a degree of polarization of more than 5:1.Wavelengths, intensity and energy of the aligning light are chosendepending on the photosensitivity of the photo-alignable material.Typically, the wavelengths are in the UV-A, UV-B and/or UV-C range or inthe visible range. Preferably, the aligning light comprises light ofwavelengths less than 450 nm. More preferred is that the aligning lightcomprises light of wavelengths less than 420 nm.

If the aligning light is linearly polarized, the polarization plane ofthe aligning light shall mean the plane defined by the propagationdirection and the polarization direction of the aligning light. In casethe aligning light is elliptically polarized, the polarization planeshall mean the plane defined by the propagation direction of the lightand by the major axis of the polarization ellipse.

The terms “anisotropic” and “anisotropy” may, for example, refer to theoptical absorption, the birefringence, the electrical conductivity, themolecular orientation, the property for alignment of other materials,for example for liquid crystals, or mechanical properties, such as theelasticity modulus. In the context of this application the term“alignment direction” shall refer to the symmetry axis of theanisotropic property.

The generation of an object from a material composition comprising aphoto-alignable material may be done by any suitable method, such ascasting, molding, including injection molding and pressure molding, orextrusion, 2D- or 3D-printing and coating. Suitable coating methods are,for example: spin-coating, blade coating, knife coating, kiss rollcoating, cast coating, slot-orifice coating, calendar coating, diecoating, dipping, brushing, casting with a bar, roller-coating,flow-coating, wire-coating, spray-coating, dip-coating, whirler-coating,cascade-coating, curtain-coating, air knife coating, gap coating, rotaryscreen, reverse roll coating, gravure coating, metering rod (Meyer bar)coating, slot die (Extrusion) coating, hot melt coating, roller coating,flexo coating. Suitable printing methods include: silk screen printing,relief printing such as flexographic printing, ink jet printing,intaglio printing such as direct gravure printing or offset gravureprinting, lithographic printing such as offset printing, or stencilprinting such as screen printing.

The object may be manufactured by depositing the material compositioncomprising the photo-alignable material on a support, which may be flator is a mold of any form.

The support may be rigid or flexible. In principle it may consist of anymaterial. Preferably, the support comprises plastic, glass or metal oris a silicon wafer. In case the support is flexible, it is preferredthat the support is a plastic or metal foil. Preferably, the surface ofthe support on which the material composition is deposited has atopographical surface structure. Topographical surface structures are,for example, lenses, such as Fresnel and lenticular lenses as well aslens arrays, including microlenses; prisms, including microprisms;gratings and structures with rectangular or triangular cross-sections.The structures may be periodic or non-periodic.

The support may be moving during the deposition of the materialcomposition comprising the photo-alignable material. For example, anobject of the material composition may be produced in a continuous rollby roll process by depositing the material composition onto a movingflexible foil, which is preferably plastic or metallic. The resultingfilm may then be wound on a roll together with the support foil or theobject may be released from the support and is then wound as a freestanding film, without the support.

Instead of depositing the material composition on a support, aphoto-alignable object of a fixed cross-sectional profile may begenerated by an extrusion process. Objects generated by extrusion may,for example, be flat or tubular films. The objects can then be cut atlength or wound up on a roll.

Preferred methods of the invention further comprise steps for generatingsurface structures in the photo-alignable object. Typical structuresare, for example, lenses, such as Fresnel and lenticular lenses as wellas lens arrays, including microlenses; prisms, including microprisms;gratings and structures with rectangular or triangular cross-sections.The exemplary types of structures mentioned above shall also include theinverse structure profiles, which are in particular used if thestructure is intended to be replicated into another material. Thestructures may be periodic or non-periodic. The term structure elementshall refer to the smallest element of a structure that may characterizethe structure. For example, if the structure comprises microlenses, suchas a microlens array, then the structure element is a microlens. In caseof a periodic structure, the structure element is the unit which isrepeated periodically. The azimuthal dimension of structure elements maycover the range from 100 nm up to the size of the object. Preferably,the smallest width of a structure element according to the invention islarger than 500 nm, more preferred larger than 5 μm and most preferredlarger than 50 μm. The structure depth may be in the range from 10 nm toseveral centimeters. Preferably, the depth of the structure is largerthan 100 nm, more preferred larger than 1 μm and most preferred largerthan 10 μm.

In one preferred method of the invention for generating photo-alignableobjects with surface structures, the material composition comprising aphoto-alignable material is casted to a mold which provides thecorresponding structure and in a later step the object generated fromthe composition comprising a photo-alignable material is removed fromthe mold.

In another preferred method of the invention for generatingphoto-alignable objects with surface structures, the structure isembossed into the surface of a photo-alignable object, during or afterpreparation of the object, using an embossing tool which provides thecorresponding structure.

Further methods for generating surface structures make use ofphoto-lithography and etching, laser ablation, self-organization of thematerial or deposition of the material composition in the required form,for example by a printing process, such as ink jet printing or3D-printing.

For generation of anisotropy in any of the photo-alignable objectsdescribed above, the method may comprise the step of exposing thephoto-alignable object to aligning light to convert the photo-alignableobject into a photo-aligned object.

In a preferred variant of the methods described above, a slave materialis applied on the surface of a photo-aligned object. Preferably, theslave material is a liquid crystal polymer (LCP) material. The slavematerial may be applied by coating and/or printing with or withoutsolvent and may be applied over the full object area of the object oronly on parts of it. The slave material shall cover at least parts ofobject but does not have to be applied over the entire area of it.Preferably, the method involves heating the slave material before orafter applying it to the object. The method may also comprise initiatingpolymerization in the slave material by thermal treatment or exposure toactinic light. Depending on the nature of the slave material, it may behelpful to perform the polymerization under inert atmosphere, such asnitrogen, or under vacuum. The slave material may contain isotropic oranisotropic dyes and/or fluorescent dyes.

In the context of the present application, a “slave material” shallrefer to any material that has the capability to establish anisotropyupon contact with a photo-aligned material. The nature of the anisotropyin the photo-aligned material and in the slave material may be differentfrom each other. For example, the slave material may exhibit lightabsorption anisotropy for visible light and therefore can act as apolarizer, whereas the anisotropy of the photo-aligned material may onlybe related to the molecular orientation. There may also be moieties ofthe photo-alignable material, for example in a co-polymer, which are notsensitive to aligning light, but create anisotropic properties becauseof interaction with the photo-sensitive moieties, which undergo aphoto-reaction upon exposure to aligning light. Such a material exhibitsproperties of a photo-alignable material and of a slave material, butshall be included in the meaning of a photo-alignable material.

A slave material may comprise polymerizable and/or non-polymerizablecompounds. Within the context of the present application the terms“polymerizable” and “polymerized” shall include the meaning of“cross-linkable” and “cross-linked”, respectively. Likewise,“polymerization” shall include the meaning of “cross-linking”.

Preferably, the slave material is a self-organizing material. Morepreferred is that the slave material is a liquid crystal material and inparticular preferred is that the slave material is a liquid crystalpolymer material.

A liquid crystal polymer (LCP) material as used within the context ofthis application shall mean a liquid crystal material, which comprisesliquid crystal monomers and/or liquid crystal oligomers and/or liquidcrystal polymers and/or cross-linked liquid crystals. In case the liquidcrystal material comprises liquid crystal monomers, such monomers may bepolymerized, typically after anisotropy has been created in the LCPmaterial due to contact with a photo-aligned material. Polymerizationmay be initiated by thermal treatment or by exposure to actinic light,which preferably comprises uv-light. A LCP-material may consist of asingle type of a liquid crystal compound, but may also be a compositionof different polymerizable and/or non-polymerizable compounds, whereinnot all of the compounds have to be liquid crystal compounds. Further,an LCP material may contain additives, for example, a photo-initiator orisotropic or anisotropic fluorescent and/or non-fluorescent dyes.

According to a second aspect of the invention there is provided aphoto-alignable object.

The object may have any form; it may be in the form of a flexible foil,but may also be rigid with any kind of shape. The object may be part ofa device, for example as a layer in a stack of layers of differentmaterials, which may have been produced one after the other.

Anisotropy is generated in the photo-alignable object by exposing it toaligning light. The anisotropy induced in a photo-alignable object maythen further be transferred to a slave material, which is brought incontact with the surface of the object, for example by a printing,coating or casting method, which include, but are not limited to:spin-coating, blade coating, knife coating, kiss roll coating, castcoating, slot-orifice coating, calendar coating, die coating, dipping,brushing, casting with a bar, roller-coating, flow-coating,injection-molding, wire-coating, spray-coating, dip-coating,whirler-coating, cascade-coating, curtain-coating, air knife coating,gap coating, rotary screen, reverse roll coating, gravure coating,metering rod (Meyer bar) coating, slot die (Extrusion) coating, hot meltcoating, roller coating, flexo coating, silk screen printer, reliefprinting such as flexographic printing, ink jet printing, 3D-printing,intaglio printing such as direct gravure printing or offset gravureprinting, lithographic printing such as offset printing, or stencilprinting such as screen printing.

Preferred applications include the use as alignment surface forswitchable liquid crystals in LCDs as well as for slave materials, forexample, for making optical retarders or polarizing films, which maycomprise an orientation pattern.

In a preferred embodiment of this invention, the photo-alignable objecthas a topographical surface structure. The structure may comprisemicroelements or arrays of microelements. Typical structures are, forexample, lenses, such as Fresnel and lenticular lenses as well as lensarrays, including microlenses; prisms, including microprisms; gratingsand structures with rectangular or triangular cross-sections. Thestructures may be periodic or non-periodic. The exemplary types ofstructures mentioned above shall also include the inverse structureprofile, which are in particular used if the structure is intended to bereplicated into another material. The azimuthal dimension of structureelements may cover the range from 100 nm up to the size of the object.Preferably, the smallest width of a structure element according to theinvention is larger than 500 nm, more preferred larger than 5 μm andmost preferred larger than 50 μm. The structure depth may be in therange from 10 nm to several centimeters. Preferably, the depth of thestructure is larger than 100 nm, more preferred larger than 1 μm andmost preferred larger than 10 μm.

Photo-alignable objects with a topographical surface structure may besimilarly photo-aligned as this is done in the state of the arttechnique and may be used to align slave materials, such as switchableliquid crystals in LCDs or LCP materials, the latter allowing to makeoptical retarders or polarizers. As the surface structure of the objectwill be formed into the slave material, the boundary of the slavematerial at the object side will also be topographically structured.Therefore, the optical properties of the slave material will bespatially modulated according to the surface structure. Typicalstructures replicated in this way are, for example, lenses, such asFresnel and lenticular lenses as well as lens arrays, includingmicrolenses; prisms, including microprisms; gratings and structures withrectangular or triangular cross-sections. The structures may be periodicor non-periodic. This enables new applications for optical elements,such as for optically anisotropic lenses in autostereoscopic 3DDisplays, as part of a system for switching between 2D and 3D mode.Other applications include brightness enhancement films for LCDs, lightout-coupling arrays for LCDs and organic light emitting devices (OLED)for displays or lighting as well as optical security elements.

FIG. 1 shows an example of a device which is based on state of the artphoto-alignment technique. In this technique a photo-alignable materialis deposited as a thin layer 2 on a substrate 1. Upon exposing the layerof photo-alignable material to aligning light, aligning capabilities aregenerated in this layer. After coating a liquid crystal layer 3 on topof the photo-aligned material, the liquid crystal material uniformlyaligns according to the direction 4 defined by the aligning light.

In the example of FIG. 2 the device 10 is based on a photo-alignableobject 11 according to the invention, which comprises a surfacestructure 12. Upon exposing the photo-alignable object to aligninglight, aligning capabilities are generated at the surface of thestructure of the object. After coating a liquid crystal layer 13 on topof the photo-aligned object, the liquid crystal material in averagealigns according to the direction 14 defined by the aligning light.

According to a third aspect of the invention there is provided a devicecontaining a photo-aligned object.

A device according to the invention comprises a slave material, whichhas been aligned by a photo-aligned object. The slave material may havebeen removed from the photo-aligned object after alignment in the slavematerial has been established. Preferably, the slave material is an LCPmaterial. The device is preferably transparent for visible light with alight transmission rate higher than 60%, more preferred higher than 80%.The slave material may contain isotropic or anisotropic dyes and/orfluorescent dyes. Preferred devices according to the invention furthercomprise a metallic or non-metallic reflector. The device preferablycomprises one or more layers for protecting the device againstmechanical of electromagnetic impact.

In a preferred embodiment of the invention, the slave material has atleast one surface which is topographically structured and is or was incontact with the photo-aligned object. Typical topographical structuresare, for example, lenses, such as Fresnel and lenticular lenses as wellas lens arrays, including microlenses; prisms, including microprisms;gratings and structures with rectangular or triangular cross-sections.The structures may be periodic or non-periodic. Preferably, thetopographical structure supports optical focusing.

As an example, FIG. 6 illustrates a method of making opticallyanisotropic lenticular lenses. FIG. 6a shows a mold 50 providing asurface profile 51 desired for lenticular lenses. In principal anymaterial, such as metal or polymer, can be used for the mold. A materialcomposition 52 comprising a photo-alignable material is deposited in themold by a suitable method, such as casting (FIG. 6b ). Depending on thekind of the material composition 52, a heating and/or uv-curing step maybe applied in order to solidify it. Subsequently, the obtainedphoto-alignable object 53 can be removed from the mold. As shown in FIG.6c , the resulting photo-alignable object 53 has a surface profile 54,which is inverse to the surface profile of a lenticular lens array,which is because the surface structure of the mold has been replicatedinto the object 53. The photo-alignable object 53 is then exposed toaligning light to convert it into a photo-aligned object with analigning direction indicated by the arrow 55. Subsequently, a LCPmaterial is deposited on the photo-aligned object 53, such that it fillsthe surface structure 54, as shown in FIG. 6d . Depending on the LCPmaterial properties, thermal treatment and/or uv-curing may be requiredto align the liquid crystal molecules and to solidify the LCP. Theresulting LCP layer has the form of a lenticular lens array 56. Theorientation direction 57 of the liquid crystal molecules is parallel tothe alignment direction 55 generated in the photo-aligned object 53. Theoptical properties of object 53 and that of the LCP material may beselected such that the lenticular lenses 56 and the object 53 togetherform an optical device 58. Because the liquid crystal molecules areuniaxially aligned, the LCP layer is birefringent. The refractive indexof the LCP along the alignment direction corresponds to theextraordinary refractive index n_(e), whereas the refractive indexperpendicular to the alignment direction corresponds to the ordinaryrefractive index n_(o). In a preferred embodiment of the invention, therefractive index of the object 53 is chosen to be about the same as oneof the two refractive indices n_(e) and n_(o). If, for example, therefractive index of the object is identical to the ordinary refractiveindex n_(o) of the LCP layer, and consequently is different from theextraordinary refractive index n_(e), then the optical property of thedevice 58 for polarized light depends on the polarization direction ofthe light. For polarized light with a polarization direction parallel tothe orientation direction 57, there will be a refractive index step atthe boundary between object 55 and the LCP material. Therefore, thedevice 58 will operate like a lenticular lens array in correspondencewith the geometry and the related refractive indices. For polarizedlight with a polarization direction perpendicular to the orientationdirection 57, however, there will be no refractive index difference atthe boundary between object 55 and the LCP material and the light willnot be refracted. Hence, depending on the polarization direction of thelight, the lens array is active or not active. In combination with anadditional optical element, which can rotate the polarization plane oflight by 90°, such as a liquid crystal cell, the lens array device 58can be switched between active and not active.

In a preferred embodiment the device comprises optically anisotropiclenses.

Devices according to the invention can, for example, be used inautostereoscopic 3D Displays, as part of a system for switching between2D and 3D mode. Other applications include brightness enhancement filmsfor LCDs, light out-coupling arrays for LCD and organic light emittingdevices (OLED), like displays or OLED lighting applications. Furtherdevices according to the invention may be used as part of backlightunits for LCDs. Preferably, devices according to the invention are usedin optical security elements.

According to a fourth aspect of the invention there is provided acomposition for the manufacturing of a photo-alignable object.

The material composition comprising a photo-alignable material maycomprise more than one type of photo-alignable materials.

The material composition comprising a photo-alignable material maycomprise additional substances which do not comprise photo-alignablemoieties. Such substances include polymers, dendrimers, oligomers,prepolymers and monomers, which may be polymerized during or after themanufacturing of the object. Examples of classes of suitable polymersare, but not limited to: polyalkylenes, such as polyethylene,polypropylene, polycycloolefine COP/COC, polybutadiene,poly(meth)acrylates, polyester, polystyrene, polyamide, polyether,polyurethane, polyimide, polyamide acid, polycarbonate,poly-vinylalcohol, poly-vinylchloride, cellulose and cellulosederivatives such as cellulose triacetate. Examples of suitable classesof monomers are: mono and multifunctional (meth)acrylates, epoxies,isocyanate, allyl derivatives and vinyl ethers.

Preferably, a photo-alignable object according to the invention does nothave a liquid crystal phase above 20° C., more preferable it does nothave a liquid crystal phase above 10° C. The reason is that liquidcrystals establish alignment by self organization, typically in smalldomains. Photo-alignment would have to compete with the random liquidcrystal alignment and would require long exposure to polarized uv-lightand/or heating the object to a temperature above the clearingtemperature of the liquid crystal material, to perform thephoto-alignment process in the isotropic phase of the material, wherethe liquid crystals have no order anymore. In any way this wouldcomplicate the alignment process. According to the above, it ispreferred that the material composition comprising a photo-alignablematerial, without any solvents that may be removed after forming anobject, does not have a liquid crystal phase above 20° C., morepreferred not above 10° C. On the other hand, it is preferred that theindividual substances of the material composition comprising aphoto-alignable material do not exhibit a liquid crystal phase above 20°C., more preferred not above 10° C.

The term substances with regard to the material composition comprising aphoto-alignable material shall not include solvents, which may be usedfor preparation of the composition and of the object and which willlater be removed, for example by drying. In other words, the meaning ofthe term substances includes only those compounds which remain in thefinal object.

In particular, the material composition comprising a photo-alignablematerial may contain additives for improving adhesion.

Further, the material composition comprising a photo-alignable materialmay contain isotropic or anisotropic dyes and/or fluorescent dyes.

Depending on the type of materials in the composition, phase separationbetween the photo-alignable material and the other substances may occur.By proper choice of the material composition it is possible to controlphase separation such that upon manufacturing an object most of thephoto-alignable material separates to the surface of the object. Thisfurther allows to reduce the amount of photo-alignable material in thecomposition. Preferably, the percentage by weight of the sum of thephoto-alignable materials in the composition is less than 50%, morepreferable less than 20% and most preferably less than 10%. Depending onthe thickness of the object that was made with the material composition,the amount of photo-alignable material may be less than 1 wt % or evenless than 0.1 wt %. In extreme cases 0.01 wt % of photo-alignablematerial is enough to still achieve sufficient alignment properties.Preferably, the photo-alignable material comprises fluorinated and/orsiloxane moieties and/or is a polysiloxane, in order to support phaseseparation.

In a preferred embodiment, a composition according to the inventioncomprises a photo-alignable material and another substance, which may bephoto-alignable or not. Both, the photo-alignable material and the othersubstance may be a polymer, a dendrimer, a oligomer, a prepolymer or amonomer. The photo-alignable material and the other substance are soselected that the monomer dipole moments of the photo-alignable materialand the other substance are different from each other. The monomerdipole moment shall refer to the dipole moment of a monomer or in caseof polymers, oligomers and prepolymers to the dipole moment of monomericunits of such polymers, oligomers and prepolymers, respectively.Preferably, the monomer dipole moments differ by more than 0.5 Debye,more preferably by more than 1 Debye and most preferred by more than 1.5Debye. The composition may contain additional photo-alignable ornon-photo-alignable substances.

A photo-alignable material for a composition for manufacturing an objectaccording to the invention may be any kind of photo-sensitive materialin which anisotropic properties can be created upon exposure to aligninglight, independent from the photo-reaction mechanism. Therefore,suitable photo-alignable materials are, for example, materials in whichupon exposure to aligning light the anisotropy is induced byphoto-dimerization, photo-decomposition, trans-cis isomerization orphoto-fries rearrangement. Preferred photo-alignable materials arethose, in which upon exposure to aligning light the created anisotropyis such that slave materials in contact with the photo-aligned materialcan be oriented. Preferably, such slave material is a liquid crystalmaterial, in particular a LCP-material.

Photo-alignable materials, as those described above, incorporatephoto-alignable moieties, which are capable of developing a preferreddirection upon exposure to aligning light and thus creating anisotropicproperties. Such photo-alignable moieties preferably have anisotropicabsorption properties. Typically, such moieties exhibit absorptionwithin the wavelength range from 230 to 500 nm. Preferably, thephoto-alignable moieties exhibit absorption of light in the wavelengthrange from 300 to 450 nm, more preferred are moieties, which exhibitabsorption in the wavelength range from 350 to 420 nm.

Preferably the photo-alignable moieties have carbon-carbon,carbon-nitrogen, or nitrogen-nitrogen double bonds.

For example, photo-alignable moieties are substituted or un-substitutedazo dyes, anthraquinone, coumarin, mericyanine, 2-phenylazothiazole,2-phenylazobenzthiazole, stilbene, cyanostilbene, fluorostilbene,cinnamonitrile, chalcone, cinnamate, cyanocinnamate, stilbazolium,1,4-bis(2-phenylethylenyl)benzene, 4,4′-bis(arylazo)stilbenes, perylene,4,8-diamino-1,5-naphthoquinone dyes, aryloxycarboxylic derivatives,arylester, N-arylamide, polyimide, diaryl ketones, having a ketonemoiety or ketone derivative in conjugation with two aromatic rings, suchas for example substituted benzophenones, benzophenone imines,phenylhydrazones, and semicarbazones.

Preparation of the anisotropically absorbing materials listed above arewell known as shown, e.g. by Hoffman et al., U.S. Pat. No. 4,565,424,Jones et al., in U.S. Pat. No. 4,401, 369, Cole, Jr. et al., in U.S.Pat. No. 4,122,027, Etzbach et al., in U.S. Pat. No. 4,667,020, andShannon et al., in U.S. Pat. No. 5,389,285.

Preferably, the photo-alignable moieties comprise arylazo,poly(arylazo), stilbene, cyanostilbene, cinnamate or chalcone.

A photo-alignable material may have the form of a monomer, oligomer orpolymer. The photo-alignable moieties can be covalently bonded withinthe main chain or within a side chain of a polymer or oligomer or theymay be part of a monomer. A photo-alignable material may further be acopolymer comprising different types of photo-alignable moieties or itmay be a copolymer comprising side chains with and withoutphoto-alignable moieties.

Polymers denotes for example to polyacrylate, polymethacrylate,polyimide, polyurethane, polyamic acids, polymaleinimide,poly-2-chloroacrylate, poly-2-phenylacrylate; unsubstituted or withC₁-C₆alkyl substituted poylacrylamide, polymethacyrlamide,poly-2-chloroacrylamide, poly-2-phenylacrylamide, polyether,polyvinylether, polyester, polyvinylester, polystyrene-derivatives,polysiloxane, straight-chain or branched alkyl esters of polyacrylic orpolymethacrylic acids; polyphenoxyalkylacrylates,polyphenoxyalkylmethacrylates, polyphenylalkylmeth-acrylates with alkylresidues of 1-20 carbon atoms; polyacrylnitril, polymethacrylnitril,cycloolephinic polymers, polystyrene, poly-4-methylstyrene or mixturesthereof.

A photo-alignable material may also comprise photo-sensitizers, forexample, ketocoumarines and benzophenones.

Further, preferred photo-alignable monomers or oligomers or polymers aredescribed in U.S. Pat. No. 5,539,074, U.S. Pat. No.6,201,087, U.S. Pat.No. 6,107,427, U.S. Pat. No.6,632,909 and U.S. Pat. No.7,959,990.

EXAMPLES Syntheses of Photo-Alignment Polymers Preparation Example A14,4,4-trifluorobutyl (E)-3-(4-hydroxyphenyl)prop-2-enoate

164.16 g of p-coumaric acid are dissolved in 1000 ml ofN-methyl-2-pyrrolidone. 152.54 g of 1,8-diazabicyclo[5,4,0]undec-7-eneare slowly added, followed by 237.99 g of 1,1,1-trifluoro-4-iodobutane.The brownish solution is heated under stirring to 70° C. and kept for 2h at this temperature. HPLC analysis shows still presence of unreactedcoumaric, additional 47.60 g of trifluoro-iodobutane are added and thereaction continued for another 2 h at 70° C.

The reaction mixture is then diluted with 5000 ml of ethyl acetate and5000 ml of aqueous 5% hydrochloric acid solution are added. Thetwo-phase mixture is stirred at room temperature for 10 minutes, theaqueous phase is removed. The organic phase is washed with 5000 ml ofaqueous 5% sodium bicarbonate solution and 5000 ml of aqueous 10% sodiumchloride solution. The remaining organic phase is diluted with 3000 mlof toluene and partly concentrated by distilling off the solvents undervacuum to leave 762 g of a brown liquid product containing some saltresidues, which are removed by filtration. Further distillation provides437 g of a liquid crude product. 400 ml of heptane are slowly added atca. 70° C. and the mixture crystallized by cooling to room temperatureand finally to 0° C. The crystalline precipitate is filtered off, washedwith a solvent mixture toluene/heptane=1/1 (v/v) and dried under vacuumat 40° C. to constant weight.

231.7 g of crystalline trifluorobutyl ester A1 are obtained, with anHPLC purity of 99.71% area.

Preparation Example A2 4,4,4-trifluorobutyl(E)-3-[4-(6-hydroxyhexoxy)phenyl]prop-2-enoate

231.00 g of trifluorobutyl ester A1 are dissolved in 1100 mldimethylformamide. 138.69 g of 6-chloro-1-hexanol are added, followed by151.98 g of finely pulverized potassium carbonate and 14.04 g ofpulverized potassium iodide. The yellow-brown suspension is heated to100° C. and stirred for 3 h at this temperature. HPLC analysis showsless than 0.5% remaining A1. The yellow suspension is cooled to roomtemperature, the solid salts are filtered off and the clear filtrate isdiluted with 5000 ml of ethyl acetate, washed with 5000 ml of aqueous 5%hydrochloric acid solution, then with 5000 ml of aqueous 5% sodiumbicarbonate solution and finally with 5000 ml of aqueous 10% sodiumchloride solution. The organic phase is diluted with 2000 ml of tolueneand partly concentrated by distilling off the solvents under vacuum togive a brown liquid product containing some salt residues, which areremoved by filtration. Further distillation provides 500 g of a liquidcrude product. 400 ml of heptane are slowly added at ca. 70° C. and themixture crystallized by cooling to room temperature, leading to a thick,crystalline mass. Cooling is continued to 0° C. and the crystallineprecipitate is filtered off, washed with heptane and dried under vacuumat room temperature to constant weight.

283.6 g of crystalline product A2 are obtained with an HPLC purity of96% area.

Preparation Example A36-[4-[(E)-3-oxo-3-(4,4,4-trifluorobutoxy)prop-1-enyl]phenoxy]hexyl2-methylprop-2-enoate

112.32 g of the product A2 are dissolved in 600 ml of toluene. 12.09 gof 4-(dimethylamino)pyridine are added, followed by 0.27 g of2,6,-Di-tert-butyl-4-methylphenol and 36.16 g of methacrylic acid. Theresulting yellow solution is cooled to 0° C. and a solution of 86.66 gof N,N′-dicyclohexyl carbodiimide in 100 ml of toluene is slowly added.After stirring at 0° C.-10° C. for 1 h, the cooling bath is removed andthe reaction mixture is stirred overnight at room temperature.

The suspension is treated with 500 ml of aqueous 5% sodium bicarbonatesolution for 30 minutes at room temperature. The aqueous phase isremoved. The organic phase is once washed with 200 ml of aqueous 5%hydrochloric acid solution and once with 200 ml of aqueous 10% sodiumchloride solution. The organic phase is filtered and partly concentratedby distilling off the solvents under vacuum. The liquid residue isfiltrated and the filtrate is further concentrated to a final volume of200 ml -250 ml. 200 ml of heptane are added and the mixture is cooled toca. −10° C. The formed crystalline precipitate is separated byfiltration, washed with cold heptane and dried under vacuum below roomtemperature.

105.33 g of crystalline monomer A3 are obtained with an HPLC purity of97.3% area.

Preparation Example A4Poly-6-[4-[(E)-3-oxo-3-(4,4,4-trifluorobutoxy)prop-1-enyl]phenoxy]hexyl2-methylprop-2-enoate

25.00 g of monomer A3 are dissolved in 187 ml N-methyl-2-pyrrolidone.The nearly colourless solution is purged by applying 5 cycles of vacuumfollowed by purging with nitrogen. The solution is then heated to 65±1°C. and when this temperature is reached, a solution of 0.125 g2,2′-Azobis(2-methylpropionitrile) in 19 ml of N-methyl-2-pyrrolidone,purged the same way, is added. Polymerization is continued for 6 hoursat 65±1° C. under stirring and then cooled to room temperature.

The solid polymer is isolated by dropping the polymer solution into 1500ml of cooled (−10° C.) methanol under vigorous stirring. The precipitateis filtered off while still cold and dried under vacuum at roomtemperature.

Polymer A4 is obtained with Mw of 92164 and Mn of 26774.

Preparation Example A5Poly-6-[4-[(E)-3-oxo-3-(4,4,4-trifluorobutoxy)prop-1-enyl]phenoxy]hexyl2-methylprop-2-enoate

25.00 g of monomer A3 are dissolved in 234 ml of toluene. The nearlycolourless solution is well purged by applying 5 cycles of vacuumfollowed by purging with nitrogen. It is heated to 65±1° C. and whenthis temperature is reached the solution of 0.13 g2,2′-Azobis(2-methylpropionitrile) in 26 ml toluene, purged the sameway, is added. Polymerization is continued for 20 hours at 65±1° C.internal temperature under stirring. A second portion of 0.13 g AlBN,dissolved in little toluene, is added and the temperature increased to75° C. Polymerization is continued for a further 20 hours. A thirdportion of 0.13 g AlBN is added and polymerization continued for 20hours at 75° C. A fourth portion of 0.13 g AlBN is added andpolymerization continued for 20 hours. The resulting polymer solutioncan be used as is or the solid polymer A5 can be isolated in the form ofa sticky resin by evaporation of the solvents, with Mw of 19989 and Mnof 11700.

Preparation Example A6 Copolymer of6-[4-[(E)-3-oxo-3-(4,4,4-trifluorobutoxy)prop-1-enyl]phenoxy]hexyl2-methylprop-2-enoate and6-[4-[(E)-3-methoxy-3-oxo-prop-1-enyl]phenoxy]hexyl2-methylprop-2-enoate

14.00 g of monomer A3 and 11.00 g of monomer6-[4-[(E)-3-methoxy-3-oxo-prop-1-enyl]phenoxy]hexyl2-methylprop-2-enoate [439661-46-8] are dissolved in 187 ml ofN-methyl-2-pyrrolidone. The solution is well purged by applying 5 cyclesof vacuum followed by purging with nitrogen. The solution is then heatedto 65±1° C. and when this temperature is reached the solution of 0.127 g2,2′-Azobis(2-methylpropionitrile) in 19 ml N-methyl-2-pyrrolidone,purged the same way, is added. Polymerization is continued for 6 hoursat 65±1° C. internal temperature under stirring and then cooled to roomtemperature.

The solid polymer is isolated by dropping the polymer solution into 1500ml of cooled (−10° C.) methanol under vigorous stirring. The precipitateis filtered off while still cold and the tough polymer dried undervacuum at room temperature.

Polymer A6 is obtained with Mw of 88374 and Mn of 35338.

Preparation Example A7 (E)-3-(4-acetoxyphenyl)prop-2-enoic Acid

164.16 g of p-coumaric acid are dissolved in 500 ml of pyridine and thesolution is cooled to 10° C. 270 g of acetic anhydride are added understirring within 20 minutes at 10-15° C. The reaction mixture is stirredovernight at room temperature. The clear, yellow-brown solution isslowly added to a mixture of 1000 g of ice and 750 ml of 25%hydrochloric acid. The resulting colourless suspension is stirred for 2h at room temperature. The solid product is filtered off, washed wellwith plenty of water and vacuum-dried at 40° C. to constant weight.204.4 g of colourless, crystalline OH-protected coumaric acid A7 areobtained with an HPLC purity of 95.2% area. The product can be furtherpurified by recrystallization in methyl ethyl ketone to the HPLC purityof 98.9% area.

Preparation Example A8 4,4,5,5,5-pentafluoropentyl(E)-3-(4-acetoxyphenyl)prop-2-enoate

A mixture of 51.55 g of OH-protected coumaric acid A7, 53.40 g of4,4,5,5,5-pentafluoropentanol and 2.50 g of 4-dimethylaminopyridine in300 ml of dichloromethane is cooled to 0° C. A solution of 61.90 gdicyclohexylcarbodiimide in 50 ml dichloromethane is added understirring within 15 minutes at 0° C. The white suspension is stirred foranother 75 minutes at 0° C. and then overnight at room temperature. Thesolid DCC urea is filtered off from the suspension and the filtrate iswashed once with 200 ml of 5% aqueous hydrochloric acid solution andtwice with 200 ml of 10% aqueous sodium chloride solution. After dryingthe organic phase over sodium sulphate, the solvent is removed bydistillation to yield 90 g of OH-protected pentafluoropentyl ester A8 ascrystallizing oil with an HPLC purity of 88.8% area. It is directly usedfor the next step.

Preparation Example A9 4,4,5,5,5-pentafluoropentyl(E)-3-(4-hydroxyphenyl)prop-2-enoate

89.98 g of OH-protected pentafluoropentyl ester A8 are dissolved in 492ml of tetrahydrofurane. 49 ml of methanol and 12.3 ml of water are addedto the solution, followed by 6.90 g of pulverized potassium carbonate.The suspension is stirred and heated at 60° C. for 2.5 h. 800 ml ofethyl acetate are added and the solution is washed with 300 ml of 5%aqueous hydrochloric acid solution. The organic phase is washed twicewith 300 ml of 10% aqueous sodium chloride solution. After drying theorganic phase over sodium sulphate and filtration, the solvent isremoved by distillation to yield 80.5 g of pentafluoropentyl ester A9(containing traces of solvent) as a crystallizing oily product with anHPLC purity of 92.1% area. The product can be recrystallized intoluene/heptane to give an HPLC purity of 94% area.

Preparation Example A10 4,4,5,5,5-pentafluoropentyl(E)-3-[4-(6-hydroxyhexoxy)phenyl]prop-2-enoate

61.37 g of pentafluoropentyl ester A9 are dissolved in 400 ml ofdimethylformamide. 31.03 g of 6-chloro-1-hexanol are added, followed by34.00 g of finely pulverized potassium carbonate and 3.14 g ofpulverized potassium iodide. The yellowish suspension is stirred andheated at 100° C. for 3 hours. The yellow suspension is cooled to roomtemperature, the solid salts are filtered off and the clear filtrate isslowly added to the mixture of 800 ml of water and 200 ml of 25% aqueoushydrochloric acid at a temperature of 5° C. The precipitated product isfiltered off and the filter cake washed well with water. It is dissolvedin 500 ml of ethyl acetate and the solution washed with 300 ml of 5%aqueous sodium bicarbonate solution and then with 300 ml of 10% aqueoussodium chloride solution. After drying the organic phase with sodiumsulphate the filtered solution is evaporated to dryness to yield 80 g ofthe hydroxyalkylated pentafluoropentyl ester A10 as orange oil with aHPLC purity 91.5% area, which crystallizes in the cold. The product canbe recrystallized in toluene/heptane to provide an improved HPLC purityof 94% area.

Preparation Example A116-[4-[(E)-3-oxo-3-(4,4,5,5,5-pentafluoropentoxy)prop-1-enyl]phenoxy]hexyl2-methylprop-2-enoate

56.15 g of hydroxyalkylated pentafluoropentylester A10 are dissolved in300 ml of toluene. 13.67 g of methacrylic acid, 1.29 g of4-dimethylaminopyridine and 0.13 g of 2,6-Di-tert-butyl-4-methylphenolare added and brought to solution. After cooling to 0° C., a solution of32.76 g dicyclohexylcarbodiimide in 50 ml toluene is added understirring within 15 minutes at 0° C. The white suspension is stirred foranother 75 minutes at 0° C. and then overnight at room temperature. 350ml of 5% aqueous sodium bicarbonate solution is added to the whitesuspension and stirring continued for 1 h. The suspension is filtered,the filter cake (mainly DCC urea) washed with toluene and the aqueousphase separated. The organic phase is washed with 500 ml of 5% aqueoushydrochloride solution and 500 ml of 10% aqueous sodium chloridesolution. After drying the organic phase over sodium sulphate thesolution is evaporated to dryness to yield 64.97 g of pentafluoropentylester methacrylate A11 as slightly yellowish, crystallizing oil. Theresulting crud product is dissolved in 400 ml dichloromethane andfiltered through a short column of 100 g silica gel (pore size 60Angström, 230-400 mesh particle size). The filtrate is evaporated todryness to yield 55.85 g of colourless, crystalline pentafluoropentylester methacrylate A11 with an HPLC purity of 95.4% area.

Preparation Example A12Poly-6-[4-[(E)-3-oxo-3-(4,4,5,5,5-pentafluoropentoxy)prop-1-enyl]phenoxy]hexyl2-methylprop-2-enoate

10.00 g of monomer A11 are dissolved in 45 ml of tetrahydrofurane. 0.05g of 2,2′-Azobis(2-methylpropionitrile are added and the solution ispurged by applying 5 cycles of vacuum followed by purging with nitrogen.The solution is stirred under nitrogen for 60 h at 60° C. The solidpolymer is isolated by dropping the polymer solution into 500 ml ofcooled (−10° C.) methanol under vigorous stirring. The precipitate isfiltered off while still cold and dried under vacuum at roomtemperature.

Polymer A12 is obtained with Mw of 211′546 and Mn 110′369.

Preparation Example A13 (3,4,5-trifluorophenyl)methyl(E)-3-(4-hydroxyphenyl)prop-2-enoate

18.18 g of p-coumaric acid are dissolved in 110 ml ofN-methyl-pyrrolidone. 16.90 g of 1,8-diazabicyclo[5,4,0]undec-7ene aredropwise added, followed by 20.00 g of 3,4,5-trifluorobenzylchlorid. Thebrownish solution is stirred at 70° C. for 3 h, cooled to roomtemperature and diluted with 500 ml of ethyl acetate. It is extractedwith 500 ml of 5% aqueous hydrochloric acid solution, followed byextraction with 500 ml of 5% aqueous sodium bicarbonate solution and 500ml of water. After drying the organic phase over sodium sulphate thesolution is filtered and evaporated to dryness to yield 32.00 g ofslightly beige crystalline product. It is recrystallized from toluene toafford 27.02 g of colourless trifluorobenzylester A13 with a purity of97.7% area (HPLC).

Preparation Example A14 (3,4,5-trifluorophenyl)methyl(E)-3-[4-(6-hydroxyhexoxy)phenyl]prop-2-enoate

29.00 g of trifluorobenzylester A13 are dissolved in 140 ml ofdimethylformamide. 15.43 g of 6-chloro-1-hexanol are added, followed by16.91 g of finely pulverized potassium carbonate and 1.56 g ofpulverized potassium iodide. The yellowish suspension is stirred andheated at 100° C. for 3 h. The yellow suspension is cooled to roomtemperature, the solid salts are filtered off and the clear filtrate isslowly added to the mixture of 800 ml of water and 200 ml of 25% aqueoushydrochloric acid at 5° C. The precipitated product is filtered off andthe filter cake well washed with water. It is then dissolved in 400 mlof ethyl acetate and the solution washed with 400 ml of 5% aqueoussodium bicarbonate solution and then with 300 ml of water. After dryingthe organic phase with sodium sulphate, the filtered solution isevaporated to dryness to yield 40.2 g of brownish oil. The resultingcrud product is dissolved in toluene and crystallized by the addition ofheptane and cooling to afford 30.48 g colourless hydroxyalkylatedcoumaric ester A14 with a HPLC purity of 90.7% area.

Preparation Example A156-[4-[(E)-3-oxo-3-[(3,4,5-trifluorophenyl)methoxy]prop-1-enyl]phenoxy]hexyl2-methylprop-2-enoate

30.00 g of hydroxyalkylated coumaric ester A14 are dissolved in 160 mlof toluene. 8.85 g of methacrylic acid, 2.96 g of4-dimethylaminopyridine and 0.07 g of 2,6-Di-tert-butyl-4-methylphenolare added and brought to solution. After cooling to 0° C., a solution of21.22 g dicyclohexylcarbodiimide in 27 ml toluene is added understirring within 15 minutes at 0° C. The white suspension is stirred foranother 75 minutes at 0° C. and then overnight at room temperature. 150ml of 5% aqueous sodium bicarbonate solution is added to the whitesuspension and stirring continued for 1 h. The suspension is filtered,the filter cake (mainly DCC urea) washed with toluene and the aqueousphase separated. The organic phase is washed with 500 ml of 5% aqueoushydrochloride solution and 500 ml of 10% aqueous sodium chloridesolution. After drying the organic phase over sodium sulphate thefiltered solution is evaporated to dryness to yield 38.37 g of brownishoil. The resulting crud product is dissolved in 800 ml dichloromethaneand filtered through a short column of 200 g silica gel (pore size 60Angström, 230-400 mesh particle size). The filtrate is evaporated todryness to yield 26.27 g of colourless, crystalline trifluorobenzylestermethacrylate A15 with an HPLC purity of 94.4% area. The product can berecrystallized in toluene/heptane to provide an improved HPLC purity of97.3% area.

Preparation Example A16Poly-6-[4-[(E)-3-oxo-3-[(3,4,5-trifluorophenyl)methoxy]prop-1-enyl]phenoxy]hexyl2-methylprop-2-enoate

8.40 g of monomer A15 are dissolved in 38 ml of tetrahydrofurane. 0.04 gof 2,2′-Azobis(2-methylpropionitrile are added and the solution purgedby applying 5 cycles of vacuum, each followed by purging with nitrogen.The solution is stirred under nitrogen for 18 h at 60° C. The solidpolymer is isolated by dropping the polymer solution into 500 ml ofcooled (−10° C.) methanol under vigorous stirring. The precipitate isfiltered off while still cold and dried under vacuum at 40° C. PolymerA16 is obtained with Mw of 290′955 and Mn of 48′432.

Preparation of Orientating Object Materials (OSM)

OSM 1

1.98 g of poly-methyl methacrylate with Mw of 15000 (Fluka) aredissolved in 8.0 g of toluene, followed by 0.02 g of polymer A4 to giveOSM1.

OSM 2

3.409 g of poly-methyl methacrylate with Mw of 15000 (Fluka) aredissolved in 6.5 g of toluene, followed by 0.091 g of polymer A4 to giveOSM 2.

OSM 3

1.9 g of poly-methyl methacrylate with Mw of 15000 (Fluka) are dissolvedin 8.0 g of toluene, followed by 0.1 g of polymer A4 to give OSM 3.

OSM 4

3.325 g of poly-methyl methacrylate with Mw of 15000 (Fluka) aredissolved in 6.5 g of toluene, followed by 0.175 g of polymer A4 to giveOSM 4.

OSM 5

3.28 g of CN9010EU (Sartomer), 3.28 g of SR351 (Sartomer) and 3.28 g ofMiramer M1183 (Miwon Specialty Chemical) are mixed under stirring. 0.1 gof polymer A4 are added, the mixture is further stirred overnight. 0.1 gof dicumyl peroxide (Aldrich) are added, the mixture is further stirredfor 1 h to give OSM 5.

OSM 6

1.88 g of CN9010EU (Sartomer), 3.76 g of SR9035 (Sartomer) and 3.76 g ofMiramer M1183 (Miwon Specialty Chemical) are mixed under stirring. 0.5 gof polymer A4 are added, the mixture is further stirred overnight. 0.1 gof dicumyl peroxide (Aldrich) are added, the mixture is further stirredfor 1 h to give OSM 6.

OSM 7

4 g of CN9010EU (Sartomer), 7.8 g of SR9035 (Sartomer) and 7.8 g ofMiramer M1183 (Miwon Specialty Chemical) are mixed under stirring. 0.2 gof polymer A4 are added, the mixture is further stirred overnight. 0.2 gof Irgacure 819 (BASF) are added, the mixture is further stirred for 1 hto give OSM 7.

OSM 8

1.88 g of CN9010EU (Sartomer), 3.76 g of SR9035 (Sartomer) and 3.76 g ofMiramer M1183 (Miwon Specialty Chemical) are mixed under stirring. 0.5 gof polymer A5 are added, the mixture is further stirred overnight. 0.1 gof Irgacure 819 (BASF) are added, the mixture is further stirred for 1 hto give OSM 8.

OSM 9

1.88 g of CN9010EU (Sartomer), 3.76 g of SR9035 (Sartomer) and 3.76 g ofMiramer M1183 (Miwon Specialty Chemical) are mixed under stirring. 0.5 gof polymer A6 are added, the mixture is further stirred overnight. 0.1 gof Irgacure 819 (BASF) are added, the mixture is further stirred for 1 hto give OSM 9.

OSM 10

1.9 g of poly-methyl methacrylate with Mw of 15000 (Fluke) are dissolvedin 8.0 g of toluene, followed by 0.1 g of polymer A12 to give OSM 10.

OSM 11

1.9 g of poly-methyl methacrylate with Mw of 15000 (Fluke) are dissolvedin 8.0 g of toluene, followed by 0.1 g of polymer A16 to give OSM 11.

OSM 12

1.49 g of cellulose acetate (Eastman CA-398-3) are dissolved in 8.43 gof tetrahydrofurane, followed by 0.08 g of polymer A12 to give OSM 12.

OSM 13

1.49 g of cellulose acetate (Eastman CA-398-3) are dissolved in 8.43 gof tetrahydrofurane, followed by 0.08 g of polymer A16 to give OSM 13.

Preparation of Polymerisable Liquid Crystal Materials (LCP)

LCP 1

1.9 g of Paliocolor LC242 (BASF) and 0.002 g of2,6-di-tert-butyl-4-methylphenol (Fluke) are melted at 80° C. Understirring 0.098 g of Irgacure 907 (BASF) are added and mixed to give LCP1.

LCP 2

1.9 g of Paliocolor LC1057 (BASF) and 0.002 g of2,6-di-tert-butyl-4-methylphenol (Fluke) are melted at 105° C. Understirring 0.098 g of Irgacure 907 (BASF) are added and mixed to give LCP2.

LCP 3

11.1 g of Benzoic acid,2,5-bis[[4-[[6-[(1-oxo-2-propenyl)oxy]hexyl]oxy]benzoyl]oxy]-, pentylester, 0.48 g of Irgacure 907 (BASF), 0.06 g of TEGO Flow 300 (Evonik),0.012 g of 2,6-di-tert-butyl-4-methylphenol (Fluke) and 0.36 g ofKayarad DPCA-20 (Nippon Kayaku) are dissolved in 28.0 g of n-butylacetate to give LCP 3.

APPLICATION EXAMPLES Application Example 1

In this example a device is made as illustrated in FIG. 3. OSM 1 iscoated with wire bar no. 0 (RK Print-Coat Instruments) on two glassplates 21, 25, which serve as support and dried at 80° C. for 4 minutes,which gives objects in the form of films with a thickness of 1 μm. Theobtained objects 22 and 24 are then exposed to linearly polarized lightat 200 mJ/cm² (280-320 nm), thereby defining first and second alignmentdirections 27, 28, respectively. Two strips 26, 27 of 40 μm thickadhesive tape are put onto the coated side, close to two parallel edges,of the first glass as spacers. The first glass is then placed on a hotplate at 60° C. Preheated LCP 1 (80° C.) is dropped onto the coated sideof the first glass. The second glass is then placed with the coated sidein contact with the LCP such that the alignment directions 27, 28 of thetwo photo-aligned objects are parallel. The thus assembled device 20 isheated at 80° C. for 10 minutes and then exposed to uv-light (Fusion UVSystems, Bulb H) at 2000 mJ/cm² in order to cure the LCP. When arrangingthe obtained device 20 between crossed polarizers, uniform orientationof the LCP in the direction 29 is observed.

Application Example 2

A device is prepared in the same way as in application example 1, butusing OSM 3 instead of OSM 1. The thickness of the OSM 1 films is 0.8μm. When arranging the obtained device between crossed polarizers,uniform orientation of the LCP is observed.

Application Example 3

OSM 2 is coated with Zehntner Coater (ZUA 2000.150 Universal applicator)with 133 μm setting onto two glass plates as a support and dried at 80°C. for 4 minutes, which results in films with a thickness of 16 μm.Using the two objects, a device is made in the same way as inapplication example 1. When arranging the obtained device betweencrossed polarizers, uniform orientation of the LCP is observed.

Application Example 4

As in application example 2, OSM 3 is coated with wire bar no. 0 (RKPrint-Coat Instruments) onto two glass plates and dried at 80° C. for 4minutes. On top of the resulting OSM 3 layer 32 of the first coatedglass plate 31, 0.5 cm wide (80 μm) strips 34 made from a cellulosetriacetate film are placed in parallel, with a distance of 0.5 cm, asillustrated in FIG. 4a . OSM 4 is coated with wire bar no. 0 to preparea film 33, still containing solvent (FIG. 4b ). After the film is driedat 80° C. for 4 minutes the strips 34 are removed to give a structuredsurface with areas comprising only film 32 and areas comprising film 33on top of film 32 (FIG. 4c ), with a thickness difference of approx. 12μm. The obtained object 35 is then exposed to linearly polarized lightat 200 mJ/cm² (280-320 nm), whereby the polarization direction isparallel to the length direction of the structure, which corresponds tothe length direction of the removed strips. A device is then made usingthe two glasses in the same way as in application example 1. Whenarranging the obtained device between crossed polarizers, uniformorientation of the LCP is observed.

Application Example 5

A device is made using OSM 3 in the same way as in application example2, with the modification, that LCP 2 is used instead of LCP 1, LCP 2 ispreheated to 105° C. before dropping it onto the object and the deviceis heated to 105° C. for 10 minutes before curing the LCP. Whenarranging the obtained device between crossed polarizers, uniformorientation of the LCP layer is observed.

Application Example 6

A device is made in the same way as in application example 4, with themodification, that LCP 2 is used instead of LCP 1, LCP 2 is preheated to105° C. before dropping it onto the object and the device is heated to105° C. for 10 minutes before curing the LCP. When arranging theobtained device between crossed polarizers, uniform orientation of theLCP is observed.

Application Example 7

OSM 5 is coated with wire bar no. 0 (RK Print-Coat Instruments) onto twoglass plates. The coatings are first cured at 150° C. for 15 minutes andthen at 200° C. for 10 minutes, resulting in films with a thickness of 1μm. Using the two objects, a device is made in the same way as inapplication example 1. When arranging the obtained device betweencrossed polarizers, uniform orientation of the LCP is observed.

Application Example 8

OSM 5 is casted on to a reflecting aluminum foil and first cured at 150°C. for 15 minutes and then at 200° C. for 10 minutes, resulting in afilm with a thickness of approximately 100 μm. The obtained object isthen exposed to linearly polarized light at 200 mJ/cm² (280-320 nm). LCP3 is spin coated at 2000 rpm for 30 seconds and dried at 55° C. for 2minutes. After cooling to room temperature, the LCP layer is UV curedunder nitrogen at 1500 mJ/cm² (300-400nm). When observing the LCP layerthrough a linear polarizer arranged above the LCP layer, uniformorientation can be seen.

Application Example 9

OSM 6 is coated with Zehntner Coater (ZUA 2000.150 Universal applicator)with 300 μm setting onto a glass plate, cured at 150° C. for 30 minutes,to give a film thickness of about 70 μm. The obtained photo-alignableobject is then exposed to linearly polarized light at 500 mJ/cm²(280-320 nm). LCP 3 is spin coated on top of the object at 2000 rpm for30 seconds and dried at 55° C. for 4 minutes. After cooling to roomtemperature, the LCP layer is UV cured under nitrogen at 1500 mJ/cm²(300-400nm). The film stack resulting from OSM6 and LCP3 coating isdelaminated from the glass plate. When arranging the film betweencrossed polarizers, uniform orientation of the LCP is observed.

Application Example 10

OSM 7 is coated with Zehntner Coater (ZUA 2000.150 Universal applicator)with 50 μm setting onto a glass plate. After waiting for 5 minutes atroom temperature the coating is cured under nitrogen with UV LED (395nm) at 4000 mJ/cm², to give a film with a thickness of about 10 μm. Theobtained photo-alignable object is then exposed to linearly polarizedlight at 1000 mJ/cm² (280-320nm). LCP 3 is spin coated at 2000 rpm for30 seconds and dried at 55° C. for 4 minutes. After cooling to roomtemperature, the LCP is UV cured under nitrogen at 1500 mJ/cm²(300-400nm). When observing the coated glass plate between crossedpolarizers, uniform orientation is seen.

Application Example 11

OSM 7 is coated with Zehntner Coater (ZUA 2000.150 Universal applicator)with 400 μm setting onto a glass plate. After 5 minutes at roomtemperature the resulting layer is cured under nitrogen at 4000 mJ/cm²(300-400nm) and has a film thickness of about 220 μm. The obtainedobject is then exposed to linearly polarized light at 1000 mJ/cm²(280-320 nm). LCP 3 is spin coated at 2000 rpm for 30 seconds and driedat 55° C. for 4 minutes. After cooling to room temperature, the LCP isUV cured under nitrogen at 1500 mJ/cm² (300-400nm). When observing thecoated glass plate between crossed polarizers, uniform orientation isseen.

Application Example 12

An embossing tool 40 is prepared from a first glass plate 41 by stickingstrips 42 of an adhesive tape parallel to each other on the glass plate,as illustrated in FIG. 5a . The distance between the strips is 0.5 cmand the width of the strips is 1.8 cm. The thickness of the tape is 50μm. The glass plate with the adhesive strips is then vapour treated withTrichloro(1H,1H,2H,2H-perfluorooctyl)silane for 5 minutes, which is thena glass embossing tool 40. OSM 8 is coated with Zehntner Coater (ZUA2000.150 Universal applicator) with 200 μm setting onto a second glassplate 43, to prepare a film 44. The glass embossing tool 40 is pressedonto the film 44, which is then cured by irradiation through the glassembossing tool with the uv light of a UV LED (395 nm) at 4000 mJ/cm².The glass embossing tool is then removed. On the second glass plate 43is now a structured film 45 with two height levels 46 and 47 (FIG. 5b ),the lower height of which is about 60 μm and the larger height is about105 μm. The so obtained photo-alignable, structured object is thenexposed to linearly polarized light at 1000 mJ/cm² (280-320 nm). LCP 3is spin coated on top of the photo-aligned, structured object 45 at 2000rpm for 30 seconds and dried at 55° C. for 4 minutes. After cooling toroom temperature, the LCP is UV cured under nitrogen at 1500 mJ/cm²(300-400nm). When the so obtained device is arranged between crossedpolarizers uniform orientation of the LCP layer is observed.

Application Example 13

OSM 9 is preheated at 50° C., filtrated and coated with Zehntner Coater(ZUA 2000.150 Universal applicator) with 50 μm setting onto a glassplate, then cured under nitrogen by irradiation with the light of a UVLED (395 nm) at 4000 mJ/cm². A film with a thickness of approximately 10μm results. The obtained object is then exposed to linearly polarizedlight at 1000 mJ/cm² (280-320nm). LCP 3 is spin coated at 2000 rpm for30 seconds and dried at 55° C. for 4 minutes. After cooling to roomtemperature, the LCP is UV cured under nitrogen at 1500 mJ/cm²(300-400nm). When observing the LCP layer between crossed polarizers,uniform orientation is seen.

Application Example 14

A device is prepared in the same way as in application example 1, butusing OSM 10 instead of OSM 1 and the resulting films with a thicknessof 1.3 μm are exposed to linearly polarized light at 1000 mJ/cm²(280-320 nm) instead of 200 mJ/cm² (280-320 nm). When arranging theobtained device between crossed polarizers, uniform orientation of theLCP is observed.

Application Example 15

A device is prepared in the same way as in application example 1, butusing OSM 11 instead of OSM 1 and the resulting films with a thicknessof 1.3 μm are exposed to linearly polarized light at 1000 mJ/cm²(280-320 nm) instead of 200 mJ/cm² (280-320 nm). When arranging theobtained device between crossed polarizers, uniform orientation of theLCP is observed.

Application Example 16

OSM 12 is coated with Zehntner Coater (ZUA 2000.150 Universalapplicator) with 100 μm setting onto a glass plate. After 10 minutes atroom temperature the coating is dried at 70° C. for 10 minutes to give adry film thickness of 13 μm. The obtained object is then exposed tolinearly polarized light at 1000 mJ/cm² (280-320 nm). LCP 3 is spincoated at 2000 rpm for 30 sec and dried at 55° C. for 4 minutes. Aftercooling to room temperature, the LCP is UV cured under nitrogen at 1500mJ/cm² (300-400nm). When observing the LCP layer between crossedpolarizers, uniform orientation is seen.

Application Example 17

A device is prepared in the same way as in application example 16, butusing OSM 13 instead of OSM 12. When observing the LCP layer betweencrossed polarizers, uniform orientation is seen.

Application Example 18

OSM 6 is coated with Zehntner Coater (ZUA 2000.150 Universal applicator)with 300 μm setting onto a glass plate, cured at 150° C. for 30 minutes,to give a film thickness of about 70 μm. The film is then removed fromthe substrate to achieve a photo-alignable object in the form a freestanding film.

Application Example 19

The free standing film obtained in application example 18 is exposed tolinearly polarized light at 500 mJ/cm² (280-320 nm). The photo-alignedobject in the form of a free standing film is then fixed on a vacuumchuck of a spin coater and LCP 3 is spin coated on top of thephoto-aligned object at 2000 rpm for 30 seconds and dried at 55° C. for4 minutes. After cooling to room temperature, the LCP layer is UV curedunder nitrogen at 1500 mJ/cm² (300-400nm). When arranging the filmbetween crossed polarizers, uniform orientation of the LCP is observed.

The invention claimed is:
 1. A method for the production of aphoto-alignable object comprising the steps providing a materialcomposition comprising a photo-alignable material, wherein the materialcomposition, without any solvents that may be removed after forming anobject, does not have a liquid crystal phase above 10° C., generation ofa photo-alignable object from the material composition, wherein thephoto-alignable object is a free standing film with a thickness largerthan 2 μm.
 2. The method according to claim 1, wherein the materialcomposition comprises a photo-alignable material and another substance,which does not comprise photo-alignable moieties.
 3. The methodaccording to claim 2, wherein the percentage by weight of the sum of thephoto-alignable materials in the composition is less than 50%.
 4. Themethod according to claim 2, wherein the photo-alignable material andthe other substance are phase separated.
 5. The method according toclaim 1, wherein the photo-alignable material comprises fluorinatedmoieties.
 6. The method according to claim 1, wherein thephoto-alignable object in the form of a free standing film is generatedon a support and in a subsequent step the object is removed from thesupport.
 7. The method according to claim 6, wherein the support has atopographical surface structure.
 8. The method according to claim 6,wherein the support is moving during generation of the photo-alignableobject in the form of a free standing film.
 9. The method according toclaim 6, wherein the support is a mold which provides a surfacestructure and the material composition comprising a photo-alighnablematerial is cast to the mold and in a later step the generatedphoto-alignable object is removed from the mold.
 10. The methodaccording to claim 1, wherein surface structures are created in thephoto-alignable object, either during or after preparation of theobject, by embossing with an embossing tool.
 11. A method for theproduction of a photo-aligned object, wherein a photo-alignable objectin the form of a free standing film produced by the method of claim 1 issubsequently exposed to aligning light to form a photo-alighned object.12. The method according to claim 11, wherein a slave material isapplied on at least part of the photo-aligned object.
 13. The methodaccording to claim 12, wherein the slave material is an LCP material.14. The method according to claim 2, wherein the photo-alighnablematerial is any of polymer structures (i), (ii) or (iii) below or aco-polymer (iv) of6-[4-[(E)-3-oxo-3-(4,4,4-trifluorobutoxy)prop-1-enyl]phenoxy]hexyl2-methylprop-2-enoate and6-[4-[(E)-3-methoxy-3-oxo-prop-1-enyl]phenoxy]hexyl2-methylprop-2-enoate:


15. The method according to claim 1, wherein the photo-alighnable objectin the form of a free standing film is prepared by extrusion.
 16. Themethod according to claim 7, wherein the depth of the topographicalsurface structure is larger than 100 nm.
 17. The method according toclaim 7, wherein the surface structure comprises microelements.
 18. Themethod according to claim 12, wherein the photo-alighned object in theform of a free standing film has a topographical surface structure andthe structure of the surface is transferred into the slave material.